1. Field of the Invention
The present invention relates to a tensioning device to tension a seat belt at the time of sudden deceleration of a vehicle, and more particularly to a tensioning device of compact structure.
2. Description of the Related Art
A tensioning device to rapidly tension a seat belt suspending member being a buckle or the like and tension a seat belt at the time of sudden vehicle deceleration is frequently provided with a reversing-prevention mechanism to prevent withdrawal of the belt again so as to reliably restrain a rider body in a tensioned state. A structure such as disclosed in for example Japanese Patent Application Laid-open No. Hei 5-345557 has been proposed as such a reversing-prevention mechanism.
However, according to the foregoing structure described in the Patent Application Laid-open, a moving member of rod configuration joined to the buckle and constituting a portion of the reversing-prevention mechanism moves linearly in a direction opposite the direction of tension action of the seat belt, and so it is necessary to assure a large movement space of the foregoing moving member during seat belt tensioning, and interference with other members surrounding the device becomes a problem.